1. Field of the Invention
The present invention relates to a receptacle used in an electric power distribution system and more particularly, to a receptacle that can prevent an accident such as a damage of an electric device and a fire in advance, which may be caused by a wire connection fault or an arc fault, by detecting an error caused by the wire connection fault when a service wire is originally distributed in the receptacle and by detecting an error caused by the arc fault generated in a current during the use of the current.
2. Description of the Related Art
Generally, a low voltage (600 V or less) network is used for a distributing board at a specific area such as a city, an industrial area, and a commercial area.
Particularly, a cable of the network is laid under the ground, being designed to be introduced from at least one location.
The cable may be damaged by a variety of causes such as thermal degradation, deterioration, moisture, and damage by rodents.
To protect the network from the causes, a circuit breaker or a receptacle has been used.
In order to insulate the defective cable and to minimize the network interference, a cut-off device such as a fuse that can cut off the cable is provided on opposite ends of the cable.
The cable cut-off device is designed to stably response to a phase-to-phase defect such as a high voltage and low impedance defect.
Meanwhile, in order to prevent the fire or the electric shock, a circuit breaker for a distributing wire and a circuit breaker for a short circuit have been used at home.
The circuit breaker for the distributing wire is used for the purpose of protecting an electric wire. That is, when a current above a rated current is used during the use of a load, the current flowing along the circuit breaker becomes higher than an allowable level, thereby generating heat by which a bimetal of the circuit breaker is bent to cut off the operation of an electric device.
In addition, when there is a short circuit between phases at a load side by an electromotive tool or other metal member, since a high current is generated in a moment, the bimetal is subject to heat so that an inner magnet is activated before the electric device is operated, to cut off the operation of the electric device.
The high current generates a large amount of magnetic field, thereby activating the magnet in the electric device.
The circuit breaker for the short circuit functions to protect a user from an electric shock by detecting a fact that the user receives the electric shock during the use of the electric device and by cutting off the electric power. The circuit breaker for the short circuit also functions as the circuit breaker for the distributing wire.
As the circuit breaker for the short circuit, aground fault-protecting receptacle having a high-sensitive detecting function is well known. Such a ground fault-protecting receptacle is disclosed in Korean Patent No. 078629, entitled “ground malfunction-protecting receptacle.”
FIG. 1 illustrates a plane view of a receptacle for protecting a ground malfunction according to the conventional art.
As shown in the drawing, the receptacle includes an insulated outer case 10 having a front cover 20, a rear cover (not shown), and a base (not shown), all of which are formed of an insulating material.
Coupled between the base and the front cover 20 is a mounting yoke 30 formed of a metal plate.
Ground terminals are formed extending from the mounting yoke 30 toward an inside of the base. A plurality of openings 22 are formed on the front cover 20. Ground terminal screws (not shown) are coupled on extending portions of the mounting yoke 30 to provide a connection of an external ground wire when the ground terminals goes in and out through the are shaped openings among the openings 22.
Provided on a central portion of the front cover 20 are a reset button 40 for resetting the operation of the receptacle 10 and a test button 50 for testing a ground fault.
Although the above-described conventional receptacle is designed to be able to detect and test the ground fault, it still has a problem that it cannot detect and test the arc fault caused by a wire damage, a mechanical and electrical stress by an excessive current and an excessive use, a wire connection defect, a mechanical damage of an insulation and wiring structure, and the like.
In addition, the conventional receptacle has a problem that the reset operation is very complicated after the fault test.
Further more, since the conventional receptacle is designed not to test the wire connection fault when the wire is originally distributed, there may be an accident such as a malfunction and damage of an electric device and a fire due to the wire connection fault.